Southwest Airlines Co. pilots were denied a request to halt contract talks with the carrier, a step that could have brought them closer to a strike.

The National Mediation Board rejected the plea from the Southwest Airlines Pilots Association, signaling on Wednesday it didn’t agree with the union’s view that further meetings would be fruitless.

“I’m disappointed but not surprised” by the decision, Casey Murray, union president, said in an interview. “We are further away today than the day we filed for release, which is truly the definition of an impasse.” 

Southwest had argued against the request, which was filed on June 29. Negotiations are scheduled to resume next week in Denver. 

Major US airlines are under pressure to secure new contracts with pilots and other worker unions to help settle expected higher labor costs. Labor vies with fuel as the top expense for airlines, and pilots are the highest paid among union workers. 

Aviators at American Airlines Group Inc. will vote on a tentative agreement this month, while United Airlines Holdings Inc. has reached a preliminary accord with pilots. Delta Air Lines Inc. workers secured a new agreement earlier this year.

“We remain confident in the mediation process and feel strongly that it will drive us to a final agreement that rewards our pilots and supports our business,” said Adam Carlisle, Southwest’s vice president of labor relations. 

The National Mediation board oversees negotiations between airlines and their unions. Talks between Southwest and its pilots began more than three years ago, and were joined by a mediator in September 2022. Important issues remain unresolved, according to the union.